The present invention relates to a method and device for sharpening and scouring grinding disks having a grinding medium such as diamond or cube-crystalline borine nitride.
Conventional methods of sharpening grinding disks of the type under discussion are carried out by means of a sharpening block applied to the outer cylindrical surface of the grinding disk.
Grinding disks with diamond and cube-crystalline borine nitride as a grinding medium are usually utilized for machining many different materials, particularly very hard iron and non-iron materials, due to the high wear resistance and some other technological advantages of the grinding disks of this type.
Principal problems occurred in the utilization of such grinding disks have been connected with high technical and financial expenses, particularly in profiling and sharpening these grinding disks. This takes place especially with profiled grinding disks in which wear can not be compensated by adjusting of the machine and therefore causes errors in the formation of the workpiece. These grinding disks must be then reprofiled in predetermined operation cycles.
For profiling diamond-and-borine-nitride grinding disks are available at the present time a number of profiling methods. A necessary profiling method is usually selected depending on the grain material utilized, such as diamond or borine nitride and also on a binder used and in dependence upon a profile of the grinding disk.
Many profiling methods are known, particularly those which are carried out with diamond rolls, diamond strips or diamond bands or diamond blocks or similar profiling tools having diamond pieces. Grinding disks also formed of rotatable profiling tools from silicon carbide or corundum have been also utilized for polishing the outer surface of the grinding disks after the latter have been profiled, particularly when a high cutting range was required.
The grain distribution in the material of the disk through the binder is too small so that an insufficient space for carrying chips away and for supplying a cooling lubricant to the disk is available. The grinding disk must in addition, in many instances, be further resharpened after being sharpened preliminarily. This process which is accompanied with tearing up, roughening or free drawing of the disk surface causes a reset of the binder with respect to the grains of the grinding medium so that no or a very small quantity of diamond or borine nitride grains would break and the contour of the grinding disk would not change.
Sharpening with a sharpening block of corundum and/or silicon carbide with a ceramic or bakelitic binder has been found particularly advantageous. The sharpening block is applied to the grinding disk by running about the disk (deep grinding) or by immersion (dipping grinding).
The utilization of conventional methods has, however, some problems. These have been caused by relatively high feeding velocities of the sharpening stones, which occur at the beginning of the sharpening process. Relatively large forces have been also exerted on the sharpening block at the beginning of the process. These large forces normally lead to substantial wear of the fine profile. On the other hand, it has been desired to obtain chip chambers of certain volumes which would be optimal for the further use of the grinding disks.